As devices that include digital systems become increasingly portable, the power consumption of a device becomes a greater priority for the designers of the device. Portable devices typically operate using a rechargeable or replaceable power source, such as batteries. Designers of portable devices typically seek to maximize the amount of time that the power source will provide adequate power to the device. By doing so, the amount of time that a device may be operated by a user before the power source needs to be recharged or replaced may be increased. Designers of portable devices typically also seek to improve the performance of the devices. Unfortunately, performance increases may add to the size or complexity of a digital system in a portable device.
Digital systems generally operate using one or more clock signals that are generated by one or more clocks in the system. The clock signals allow digital circuits a system to perform operations in an orderly and synchronized manner. As the components that make up a digital system becomes faster, the system may become operable with clock signals that have higher frequencies. These higher frequencies may cause an increase in the performance of the system. Unfortunately, the amount of power that is consumed by the system typically increases with an increase in the frequency of a clock signal.
It would be desirable to be able to provide clock signals in a digital system in a way that both maximizes the performance of the system and minimizes power consumption by the system.